serial: support 16-bit register interface for console
Currently, 8-bit (MMIO) and 32-bit (MMIO32) register interfaces are
supported for the 8250 console, but the 16-bit (MMIO16) is not.
The 8250 UART device on my board is connected to a 16-bit bus and
my main motivation is to use earlycon with it.
(Refer to arch/arm/boot/dts/uniphier-support-card.dtsi)
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index f096360..07f7393 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -71,10 +71,16 @@
return -EINVAL;
switch (port->iotype) {
+ case UPIO_MEM:
+ port->mapbase = addr;
+ break;
+ case UPIO_MEM16:
+ port->regshift = 1;
+ port->mapbase = addr;
+ break;
case UPIO_MEM32:
case UPIO_MEM32BE:
- port->regshift = 2; /* fall-through */
- case UPIO_MEM:
+ port->regshift = 2;
port->mapbase = addr;
break;
case UPIO_PORT:
@@ -91,10 +97,11 @@
strlcpy(device->options, options, length);
}
- if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32 ||
- port->iotype == UPIO_MEM32BE)
+ if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 ||
+ port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE)
pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
(port->iotype == UPIO_MEM) ? "" :
+ (port->iotype == UPIO_MEM16) ? "16" :
(port->iotype == UPIO_MEM32) ? "32" : "32be",
(unsigned long long)port->mapbase,
device->options);